Document similarity calculation method facing cloud storage based on fully homomorphic password technology

Abstract

The invention discloses a document similarity calculation method facing cloud storage based on a fully homomorphic password technology. The method comprises the following steps that a data owner uploads a document ID, an encrypted document cryptograph and a cryptograph of a document Hash value to a cloud server; a public key certificate is issued to a cloud service provider and a data user; the data user encrypts a simhash value of a document with a similarity to be calculated and uploads to the cloud service provider; the cloud service provider carries out fully homomorphic addition operation of a document simhash cryptograph value to be calculated and a data owner document simhash cryptograph value and returns an operation result to the data owner; the data owner acquires Hamming distances between the documents and returns a document ID with a top distance sorting to the cloud service provider. By using the method, the calculation is performed under a cryptograph state. During a calculation process, any information related to the document is not revealed to the cloud service provider and other attackers so that a data secret of the data owner and a query data secret of the data user are protected.

Description

technical field [0001] The invention belongs to the field of computer-related software, and more specifically relates to a cloud-storage-oriented document similarity calculation method based on fully homomorphic encryption technology. Background technique [0002] With the development of cloud computing-related technologies, major companies have launched free cloud disk (also known as network disk) storage services, such as Baidu Cloud Disk, Tencent Weiyun, Jinshan Kuaipan, etc., because of their large capacity and can be accessed at any time. The network can be accessed at any time, and it has more and more users. However, its security issues, especially the privacy protection of user document data, have not been promised by service providers. A common way to solve this problem is to encrypt the document by the user, and upload the encrypted ciphertext information to the cloud service provider. When the encrypted data uploaded to the cloud service provider reaches a certa...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the above defects or improvement needs of the prior art, the present invention provides a cloud-storage-oriented document similarity calculation method and system based on fully homomorphic cr

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